What is the difference between rxjava2 and rxkotlin?

the thing is RX stands for Reactive Extensions , and Rx Java , Rx Kotlin or Rx Swift all are the implementation of Reactive Extensions in that particular language.

What is RxJAVA? RxJava is a Java VM implementation of Reactive Extensions. where we can create asynchronous data stream on any thread, transform it and these asynchronous data streams can be consumed by Observers on any thread.

What is RxKotlin? RxKotlin is a Kotlin implementation of Reactive Extensions.

What is RxAndroid? It is specific to Android Platform with some more added classes on top of RxJava.

for more details , visit my collection of rxjava simple examples https://github.com/myJarvis/Intro_to_RxJava .

and to more clarify , RxKotlin has some convenient extension functions which comes with Kotlin.

You can either use {RxJava & RxAndroid} or {RxKotlin}

You can use RxJava with Kotlin out-of-the-box

Since Kotlin is 100% interoperable with Java, you can use most Java libraries in your Kotlin projects without any difficulties—and the RxJava library is no exception.

There is a dedicated RxKotlin library, which is a Kotlin wrapper around the regular RxJava library. This wrapper provides extensions that optimize RxJava for the Kotlin environment and can further reduce the amount of boilerplate code you need to write.

If you are using rxkotlin you just need to add the following line

implementation 'io.reactivex:rxkotlin:x.y.z'

and if you want to use rxjava2 you need to include the other dependencies i.e

implementation 'io.reactivex.rxjava2:rxjava:2.2.4'
implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'

but if you are using Kotlin as your programming language I will recommend you using rxkotlin

More detail refer to this link

As you can see at https://mvnrepository.com/artifact/io.reactivex.rxjava2/rxkotlin/2.3.0, rxkotlin depends on rxjava. So it's automatically added as a transitive dependency unless you specifically exclude it.

Unsurprisingly, rxkotlin does not depend on rxandroid so you do need to add that if you want to use it. Both rxandroid and rxkotlin use the same rxjava types, so they can interoperate freely.